1. Field of the Invention
This invention relates to film-forming polymer compositions used in the coatings, mastics, adhesives, caulks and film field.
2. Description of the Prior Art
Film-forming solution polymer compositions are well known in the coatings, adhesives, caulks, and mastics fields. Recently it has been suggested to modify film-forming polymer solutions with insoluble reinforcing polymeric particles wherein said particles ae separately prepared, and are based on different polymer compositions from the film-forming polymer itself. For example, Kanda et al, U.S. Pat. No. 4,461,870, discloses film-forming polymer having functional groups capable of reacting with a crosslinking agent, an organic diluent for said polymer and crosslinking agent and, separately-prepared, insoluble polymer microparticles ("microgels") composed of a crosslinked copolymer of alpha, beta ethylenically unsaturated monomers, said microparticles carrying a resinous portion, different from said film-forming polymer, having an amphoionic group of the formula --N--R--Y where R is alkylene or phenylene and Y is --COOH or --SO.sub.3 H. The Kanda et al systems are useful for high solids coating compositions. The Kanda et al objective is to provide microparticles of polymer that are easily prepared without using any harmful emulsifier or stabilizing agent and are directly added to a coating composition as they are.
One disadvantage to the Kanda et al systems and other prior art polymeric reinforcing particle systems is the requirement of separate preparation and isolation of such particles. Another disadvantage is the requirement of a specialized amphoionic stabilizer which would increase the water-sensitivity.
U.S. Pat. No. 4,529,765 discloses a coating composition comprising a solvent and a binder containing an ethylenically-unsaturated acrylic polymer and an amino acrylic polymer. The '765 patent does not teach or suggest particle-reinforced solution polymer compositions wherein the reinforcing particles are prepared in situ and chemically grafted to the solution polymer.
U.S. Pat. No. 4,598,111 discloses coating compositions containing a soluble film forming synthetic resin, an organic solvent, and insoluble, emulsion-polymerized polymer microparticles. The '111 patent involves separate preparation and isolation of the polymer microparticles and does not teach or suggest in situ preparation of the polymer microparticles and chemical grafting of said microparticles to the soluble resin.